Milankovitch Cycles
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Started by cutworm - May 21, 2023, 11:16 p.m.

The long term cycles that affect earth's temperature. How and Why.


(139) What Milankovitch Cycles Will Do To Earth - YouTube

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By metmike - May 22, 2023, 12:17 a.m.
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Outstanding video/topic, cutworm......thanks!


Helps us to appreciate how our current climate is an OPTIMUM not a crisis and that it's cold that is the real threat. 


More stuff for those that like to read and go at their own pace.

Milankovitch (Orbital) Cycles and Their Role in Earth's Climate

https://climate.nasa.gov/news/2948/milankovitch-orbital-cycles-and-their-role-in-earths-climate/

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https://en.wikipedia.org/wiki/Milankovitch_cycles

Milankovitch cycles describe the collective effects of changes in the Earth's movements on its climate over thousands of years. The term was coined and named after Serbian geophysicist and astronomerMilutin Milanković. In the 1920s, he hypothesized that variations in eccentricity, axial tilt, and precession combined to result in cyclical variations in the intra-annual and latitudinal distribution of solar radiation at the Earth's surface, and that this orbital forcing strongly influenced the Earth's climatic patterns.[1][2]

Planets orbiting the Sun follow elliptical (oval) orbits that rotate gradually over time (apsidal precession). The eccentricity of this ellipse, as well as the rate of precession, are exaggerated for visualization.

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Holocene climatic optimum

The Holocene Climate Optimum (HCO) was a warm period that occurred in the interval roughly 9,500 to 5,500 years ago BP,[1] with a thermal maximum around 8000 years BP. It has also been known by many other names, such as Altithermal, Climatic Optimum, Holocene Megathermal, Holocene Optimum, Holocene Thermal Maximum, Hypsithermal, and Mid-Holocene Warm Period.

The warm period was followed by a gradual decline, of about 0.1 to 0.3 °C per millennium, until about two centuries ago (when this trend was rapidly reversed due to human-produced greenhouse gas emissions). However, on a sub-millennial scale, there were regional warm periods superimposed on this decline.

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metmike: It was this warm 1,000 years ago-Medieval Warm period.

2,000 years ago-Roman Warm Period and ~3,500 years ago-Minoan Warm Period.

                climate and cycles            

                            Started by bear - Nov. 3, 2022, 2:59 p.m.      

      https://www.marketforum.com/forum/topic/90279/

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The Holocene Climate Optimum warm event consisted of increases of up to 4 °C near the North Pole (in one study, winter warming of 3 to 9 °C and summer of 2 to 6 °C in northern central Siberia).[5]Northwestern Europe experienced warming, but there was cooling in Southern Europe.[6] 

Of 140 sites across the western Arctic, there is clear evidence for conditions that were warmer than now at 120 sites. At 16 sites for which quantitative estimates have been obtained, local temperatures were on average 1.6±0.8 °C higher during the optimum than now. Northwestern North America reached peak warmth first, from 11,000 to 9,000 years ago, but the Laurentide Ice Sheet still chilled eastern Canada. Northeastern North America experienced peak warming 4,000 years later. Along the Arctic Coastal Plain in Alaska, there are indications of summer temperatures 2–3 °C warmer than now.[10] Research indicates that the Arctic had less sea ice than now.[11]


Milankovitch cycles

 

Milankovitch cycles.

The climatic event was probably a result of predictable changes in the Earth's orbit (Milankovitch cycles) and a continuation of changes that caused the end of the last glacial period.[citation needed]

The effect would have had the maximum heating of the Northern Hemisphere 9,000 years ago, when the axial tilt was 24° and the nearest approach to the Sun (perihelion) was during the Northern Hemisphere's summer. The calculated Milankovitch Forcing would have provided 0.2% more solar radiation (+40 W/m2) to the Northern Hemisphere in summer, which tended to cause more heating. There seems to have been the predicted southward shift in the global band of thunderstorms, the Intertropical Convergence Zone.[citation needed]

However, orbital forcing would predict maximum climate response several thousand years earlier than those observed in the Northern Hemisphere. The delay may be a result of the continuing changes in climate, as the Earth emerged from the last glacial period and related to ice–albedo feedback. Different sites often show climate changes at somewhat different times and lasting for different durations. At some locations, climate changes may have begun as early as 11,000 years ago or have persisted until 4,000 years ago. As noted above, the warmest interval in the far south significantly preceded warming in the north.[citation needed]

By 12345 - May 22, 2023, 12:48 p.m.
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45+ YEARS AGO ~ AN ELDERLY WOMAN I'D KNOWN ALL MY LIFE, TOLD ME SHE REMEMBERS HAVING SNOW IN JUNE, ONE YEAR... ON HER DAUGHTERS' 16TH BIRTHDAY.

HOW DID SHE REMEMBER IT SO DISTINCTLY?  LOL  SHE'D GONE OUT TO HER ROSE GARDEN TO CUT HER DAUGHTER A ROSE... THE ROSES WERE LACED WITH A LIGHT DUSTING OF SNOW, ON THEM ALL.  

I'M GUESSING IT MUST HAVE BEEN IN THE 1920 - 1930 ERA.

INTERESTING VIDEO ~ THANKS, CUTWORM ✔

By metmike - May 22, 2023, 4:33 p.m.
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Thanks, Jean.

Been looking to try to find anything in the weather records of any snow in June since 1900 in the state of Ohio.,

This is the best I have so far:

Discover the Biggest Snowstorms to Ever Hit Ohio in May… Yes, May!

https://a-z-animals.com/blog/discover-the-biggest-snowstorm-to-ever-hit-ohio-in-may-yes-may/

By metmike - May 22, 2023, 4:51 p.m.
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Jean,

Maybe your friend lived in a previous life that was around in 1816 (-:


The Year Without a Summer: Mount Tambora Volcanic Eruption

https://www.almanac.com/year-without-summer-mount-tambora-volcanic-eruption


The Volcanic Eruption of Mt. Tambora

 A 13,000-foot-high volcano on the island of Sumbawa, near Bali, Indonesia, was the primary cause of the Year Without a Summer. The eruption happened in April of 1815 and was one of the greatest volcanic eruptions in history. Its toll: perhaps as many as 90,000 lives. 

Mt. Tambora ejected immense amounts of volcanic ash into the upper atmosphere, where it was carried around the world by the jet stream. The volcanic dust covered Earth like a great cosmic umbrella, dimming the Sun’s effectiveness during the whole cold year. This resulted in a further reduction in solar irradiance, which brought record cold to much of the world during the following summer. Such an eruption would explain the appearance of the 1816 Sun as “in a cloud of smoke.”


The unusual cold played havoc with agricultural production in many parts of the world, directly or indirectly creating crop failures, dramatic increases in food prices, famines, cultural disruptions, and epidemics of cholera and other diseases. There were major weather events across the United States (which numbered 18 states at the time, with Vermont, Kentucky, Tennessee, Ohio, and Louisiana having been added to the original 13).

Wild Weather Events in the Summer of 1816

  • May frosts killed off most crops in upstate New York and the higher elevations of Massachusetts, New Hampshire, and Vermont.
  • On June 6, snow fell in Albany, New York, and Dennysville, Maine.
  • In Cape May, New Jersey, frost was reported five nights in a row in late June, causing extensive crop damage.
  • Lake and river ice was observed as far south as northwestern Pennsylvania in July, with frost reported as far south as Virginia on August 20 and 21.
  • Rapid, dramatic temperature changes occurred frequently, as temperatures sometimes went from above-normal summer levels to near freezing within hours. U.S. grain prices at least quadrupled, and oat prices increased almost eightfold.
  • Famine, riots, arson, and looting occurred in many European cities, while China suffered from massive crop failures and disastrous floods, and a disruption in the Indian summer monsoon season spread a cholera outbreak from the River Ganges all the way to Moscow.

Climate of the Little Ice Age and weather of 1816 =CATASTROPHIC CRISIS

+1 Deg C and planet greening up from beneficial CO2 in 2023 = CLIMATE OPTIMUM


By 12345 - May 22, 2023, 6:38 p.m.
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1816?????????  LOL  GOOD ONE, MIKE.   

IN THOSE SNOW YEARS, THE LAKE MUST'VE BEEN PRETTY COLD!

AT LEAST IT WASN'T RAININ' OR SNOWIN' FROGS!  LOL